/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.tomcat.util.http.fileupload;

import java.util.Iterator;

/**
 * <p> This class provides support for accessing the headers for a file or form
 * item that was received within a <code>multipart/form-data</code> POST
 * request.</p>
 *
 * @since 1.2.1
 */
public interface FileItemHeaders {

	/**
	 * Returns the value of the specified part header as a <code>String</code>.
	 * <p>
	 * If the part did not include a header of the specified name, this method
	 * return <code>null</code>.  If there are multiple headers with the same
	 * name, this method returns the first header in the item.  The header
	 * name is case insensitive.
	 *
	 * @param name a <code>String</code> specifying the header name
	 * @return a <code>String</code> containing the value of the requested
	 * header, or <code>null</code> if the item does not have a header
	 * of that name
	 */
	String getHeader(String name);

	/**
	 * <p>
	 * Returns all the values of the specified item header as an
	 * <code>Iterator</code> of <code>String</code> objects.
	 * </p>
	 * <p>
	 * If the item did not include any headers of the specified name, this
	 * method returns an empty <code>Iterator</code>. The header name is
	 * case insensitive.
	 * </p>
	 *
	 * @param name a <code>String</code> specifying the header name
	 * @return an <code>Iterator</code> containing the values of the
	 * requested header. If the item does not have any headers of
	 * that name, return an empty <code>Iterator</code>
	 */
	Iterator<String> getHeaders(String name);

	/**
	 * <p>
	 * Returns an <code>Iterator</code> of all the header names.
	 * </p>
	 *
	 * @return an <code>Iterator</code> containing all of the names of
	 * headers provided with this file item. If the item does not have
	 * any headers return an empty <code>Iterator</code>
	 */
	Iterator<String> getHeaderNames();

}
